1. Field of the Invention
The present invention relates to a push-lock and, more particularly, to a push-lock which is simple in structure and easy to be assembled.
2. Description of Related Art
Push-locks are known for their closing in a manner of simply depressing cylinders. As shown in FIG. 8, a well-known push-lock includes a tubular body (70) having a rotary inner cylinder (71) and a latch (72) movably and rotatably received in the cylinder (71). The latch (72) has a back spring (73) compressed between the inner cylinder (71) and a retainer (74) fastened thereto, and a bore (75) for receiving a laterally movable pin (76).
The laterally movable pin (76) is further spring-loaded by a secondary spring (77) in such a way that the pin (76) may be extended into a curved groove (78) defined in the cylinder (71) when the latch (72) is depressed, i.e. moved relative to the cylinder (71) in a direction as denoted by an arrow in FIG. 8, thus fastening the latch (72) to the cylinder (71) and in turn to the tubular body (70), via the movable pin (76).
The push-lock can only be opened by turning the rotary cylinder (71) relative to the latch (72) with a correct key (not shown). As a result of the rotation of the cylinder (71), the pin (76) will be pressed back into the bore (75) by a wall defining the curved groove (78), thereby allowing the latch (72) to be moved back to its original position under the action of the back spring (73).
FIG. 9 shows another push-lock substantially similar to the one described above. This push-lock includes a rotary cylinder (80) having an off-centered cam (81) for operating a laterally movable pin (82) disposed in a backward-extending latch (83). The latch (83) and the rotary cylinder (80) are movable together axially in a tubular body (84) and tend to be moved by a back spring (86) to a front position relative to the tubular body (84).
However, the movable pin (82) is urged by a secondary spring (85) in such a way that the pin (82) may be extended into a hole (841) defined in the tubular body (84) when the cylinder (80) is depressed, thereby fastening the latch (83) to the tubular body (84), via the movable pin (82).
This push-lock can be opened by turning the rotary cylinder (80) with a correct key (not shown). As a result, the laterally movable pin (82) is moved downward by the off-centered cam (81) of the turning cylinder (80). At the moment when the pin (82) is released from the hole (841) of the tubular body (84), the latch (83) and the cylinder (80) are moved back to their original or front position by the action of the back spring (86).
Although the two push-locks can be closed simply by depressing the latch (72) or the cylinder (80), they share a common problem of having a complicated structure, which will increase the production cost.
One of the resolutions to the above-mentioned problem is disclosed in a push-lock of a different type, as shown in FIG. 10. The push-lock here includes a tubular body (90) formed with a longitudinal groove (91) and an L-shaped slot (92), with a cylinder (93) being movable in the tubular body (90) between a front position and a rear position, via a stud (not numbered) extending from the cylinder (93) into the longitudinal groove (91).
The cylinder (93) is formed with a rotary latch (94) that has an integral flange (95) rotatably connected to the cylinder (93), with a pin (97) extending from the flange (95) into the L-shaped groove (92) of the tubular body (90). The rotary latch (94) is further spring-loaded by a pre-twisted spring (96) in such a way that the rotary latch (94) may have a tendency to turn with respect to the body (90).
Therefore, the pin (97) will slide into the circumferential stop portion of the L-shaped groove (92), due to the tendency of the latch (94), when the cylinder (93) is depressed, i.e. moved from its front position to its rear position against the action of the spring (96). This fastens the latch (94) and hence the cylinder (93) to the tubular body (90).
The push-lock here is also opened by turning the rotary latch (94) relative to the cylinder (93) with a correct key (not shown). Once the latch (94) is turned so that the pin (97) is released from the circumferential stop portion of the groove (92), the cylinder (93) with the rotary latch (94) will be moved back from the rear position back to the front position.
This push-lock is simplified in structure. However, it is not easy to be assembled, for the action of the pre-twisted spring (96) makes the pin (97) much harder to be extended correctly into the flange (97) through the groove (92) of the body (90).
Therefore, it is an objective of the invention to provide a push-lock to mitigate and/or obviate the aforementioned problems.
The object of the present invention is to provide a push-lock which is simple in structure.
Another object of the present invention is to provide a push-lock which is easy to be assembled.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.